Deprecate requirements harder

Remove more Requirement logic to enable future removal of default
formula logic. Also, output deprecations, convert symbol requirement
usage to deps and simplify the compatibility code for the direct
Requirement usage.

9 files changed, 129 insertions, 385 deletions

diff --git a/Library/Homebrew/compat/dependency_collector.rb b/Library/Homebrew/compat/dependency_collector.rb
index 652cf370b..1c91f2283 100644
--- a/Library/Homebrew/compat/dependency_collector.rb
+++ b/Library/Homebrew/compat/dependency_collector.rb
@@ -27,57 +27,42 @@ class DependencyCollector
       odeprecated "'depends_on :tex'"
       TeXRequirement.new(tags)
     when :autoconf, :automake, :bsdmake, :libtool
-      output_deprecation(spec, tags)
+      output_deprecation(spec)
       autotools_dep(spec, tags)
     when :cairo, :fontconfig, :freetype, :libpng, :pixman
-      output_deprecation(spec, tags)
+      output_deprecation(spec)
       Dependency.new(spec.to_s, tags)
     when :ant, :expat
-      # output_deprecation(spec, tags)
+      output_deprecation(spec)
       Dependency.new(spec.to_s, tags)
     when :libltdl
       tags << :run
-      output_deprecation("libtool", tags)
+      output_deprecation("libtool")
       Dependency.new("libtool", tags)
     when :apr
-      output_deprecation(spec, tags, "apr-util")
+      output_deprecation(spec, "apr-util")
       Dependency.new("apr-util", tags)
     when :fortran
-      # output_deprecation(spec, tags, "gcc")
-      FortranRequirement.new(tags)
+      output_deprecation(spec, "gcc")
+      Dependency.new("gcc", tags)
     when :gpg
-      # output_deprecation(spec, tags, "gnupg")
-      GPG2Requirement.new(tags)
+      output_deprecation(spec, "gnupg")
+      Dependency.new("gnupg", tags)
     when :hg
-      # output_deprecation(spec, tags, "mercurial")
-      MercurialRequirement.new(tags)
+      output_deprecation(spec, "mercurial")
+      Dependency.new("mercurial", tags)
     when :mpi
-      # output_deprecation(spec, tags, "open-mpi")
-      MPIRequirement.new(*tags)
-    when :emacs
-      # output_deprecation(spec, tags)
-      EmacsRequirement.new(tags)
-    when :mysql
-      # output_deprecation(spec, tags)
-      MysqlRequirement.new(tags)
-    when :perl
-      # output_deprecation(spec, tags)
-      PerlRequirement.new(tags)
-    when :postgresql
-      # output_deprecation(spec, tags)
-      PostgresqlRequirement.new(tags)
+      output_deprecation(spec, "open-mpi")
+      Dependency.new("open-mpi", tags)
     when :python, :python2
-      # output_deprecation(spec, tags)
-      PythonRequirement.new(tags)
+      output_deprecation(spec, "python")
+      Dependency.new("python", tags)
     when :python3
-      # output_deprecation(spec, tags)
-      Python3Requirement.new(tags)
-    when :rbenv
-      # output_deprecation(spec, tags)
-      RbenvRequirement.new(tags)
-    when :ruby
-      # output_deprecation(spec, tags)
-      RubyRequirement.new(tags)
+      output_deprecation(spec, "python3")
+      Dependency.new("python3", tags)
+    when :emacs, :mysql, :perl, :postgresql, :rbenv, :ruby
+      output_deprecation(spec)
+      Dependency.new(spec, tags)
     else
       _parse_symbol_spec(spec, tags)
     end
@@ -88,13 +73,8 @@ class DependencyCollector
     Dependency.new(spec.to_s, tags)
   end
 
-  def output_deprecation(dependency, tags, new_dependency = dependency)
-    tags_string = if tags.length > 1
-      " => [:#{tags.join ", :"}]"
-    elsif tags.length == 1
-      " => :#{tags.first}"
-    end
+  def output_deprecation(dependency, new_dependency = dependency)
     odeprecated "'depends_on :#{dependency}'",
-                "'depends_on \"#{new_dependency}\"#{tags_string}'"
+                "'depends_on \"#{new_dependency}\"'"
   end
 end
diff --git a/Library/Homebrew/compat/requirements.rb b/Library/Homebrew/compat/requirements.rb
index 304dd2504..bffc5f5f1 100644
--- a/Library/Homebrew/compat/requirements.rb
+++ b/Library/Homebrew/compat/requirements.rb
@@ -1,76 +1,134 @@
 require "requirements"
-require "compat/requirements/emacs_requirement"
-require "compat/requirements/fortran_requirement"
 require "compat/requirements/language_module_requirement"
-require "compat/requirements/mpi_requirement"
-require "compat/requirements/perl_requirement"
-require "compat/requirements/python_requirement"
-require "compat/requirements/ruby_requirement"
-require "compat/requirements/tex_requirement"
 
-class MysqlRequirement < Requirement
+class CVSRequirement < Requirement
   fatal true
-  default_formula "mysql"
-  satisfy { which "mysql_config" }
+  satisfy do
+    odeprecated("CVSRequirement", "'depends_on \"cvs\"'")
+    which "cvs"
+  end
 end
 
-class PostgresqlRequirement < Requirement
+class EmacsRequirement < Requirement
   fatal true
-  default_formula "postgresql"
-  satisfy { which "pg_config" }
+  satisfy do
+    odeprecated("EmacsRequirement", "'depends_on \"cvs\"'")
+    which "emacs"
+  end
 end
 
-class RbenvRequirement < Requirement
+class FortranRequirement < Requirement
   fatal true
-  default_formula "rbenv"
-  satisfy { which "rbenv" }
+  satisfy do
+    odeprecated("FortranRequirement", "'depends_on \"cvs\"'")
+    which "gfortran"
+  end
 end
 
-class CVSRequirement < Requirement
+class GitRequirement < Requirement
+  fatal true
+  satisfy do
+    odeprecated("GitRequirement", "'depends_on \"cvs\"'")
+    which "git"
+  end
+end
+
+class GPG2Requirement < Requirement
   fatal true
-  default_formula "cvs"
-  satisfy { which "cvs" }
+  satisfy do
+    odeprecated("GPG2Requirement", "'depends_on \"cvs\"'")
+    which "gpg"
+  end
 end
 
 class MercurialRequirement < Requirement
   fatal true
-  default_formula "mercurial"
-  satisfy { which "hg" }
+  satisfy do
+    odeprecated("MercurialRequirement", "'depends_on \"cvs\"'")
+    which "hg"
+  end
 end
 
-class GPG2Requirement < Requirement
+class MPIRequirement < Requirement
   fatal true
-  default_formula "gnupg"
-  satisfy { which "gpg" }
+  satisfy do
+    odeprecated("MPIRequirement", "'depends_on \"cvs\"'")
+    which "mpicc"
+  end
 end
 
-class GitRequirement < Requirement
+class MysqlRequirement < Requirement
+  fatal true
+  satisfy do
+    odeprecated("MysqlRequirement", "'depends_on \"cvs\"'")
+    which "mysql_config"
+  end
+end
+
+class PerlRequirement < Requirement
+  fatal true
+  satisfy do
+    odeprecated("PerlRequirement", "'depends_on \"cvs\"'")
+    which "perl"
+  end
+end
+
+class PostgresqlRequirement < Requirement
+  fatal true
+  satisfy do
+    odeprecated("PostgresqlRequirement", "'depends_on \"cvs\"'")
+    which "pg_config"
+  end
+end
+
+class PythonRequirement < Requirement
+  fatal true
+  satisfy do
+    odeprecated("PythonRequirement", "'depends_on \"cvs\"'")
+    which "python"
+  end
+end
+
+class Python3Requirement < Requirement
   fatal true
-  default_formula "git"
-  satisfy { Utils.git_available? }
+  satisfy do
+    odeprecated("Python3Requirement", "'depends_on \"cvs\"'")
+    which "python3"
+  end
+end
+
+class RbenvRequirement < Requirement
+  fatal true
+  satisfy do
+    odeprecated("RbenvRequirement", "'depends_on \"cvs\"'")
+    which "rbenv"
+  end
+end
+
+class RubyRequirement < Requirement
+  fatal true
+  satisfy do
+    odeprecated("RubyRequirement", "'depends_on \"cvs\"'")
+    which "ruby"
+  end
 end
 
 class SubversionRequirement < Requirement
   fatal true
-  default_formula "subversion"
-  satisfy { Utils.svn_available? }
-end
-
-XcodeDependency            = XcodeRequirement
-MysqlDependency            = MysqlRequirement
-PostgresqlDependency       = PostgresqlRequirement
-GPGDependency              = GPG2Requirement
-GPGRequirement             = GPG2Requirement
-TeXDependency              = TeXRequirement
-MercurialDependency        = MercurialRequirement
-GitDependency              = GitRequirement
-FortranDependency          = FortranRequirement
-JavaDependency             = JavaRequirement
-LanguageModuleDependency   = LanguageModuleRequirement
-MPIDependency              = MPIRequirement
-OsxfuseDependency          = OsxfuseRequirement
-PythonDependency           = PythonRequirement
-TuntapDependency           = TuntapRequirement
-X11Dependency              = X11Requirement
-ConflictsWithBinaryOsxfuse = NonBinaryOsxfuseRequirement
-MinimumMacOSRequirement    = MacOSRequirement
+  satisfy do
+    odeprecated("SubversionRequirement", "'depends_on \"cvs\"'")
+    which "svn"
+  end
+end
+
+class TeXRequirement < Requirement
+  fatal true
+  cask "mactex"
+  download "https://www.tug.org/mactex/"
+  satisfy do
+    odeprecated("TeXRequirement", "'depends_on \"cvs\"'")
+    which("tex") || which("latex")
+  end
+end
+
+MinimumMacOSRequirement = MacOSRequirement
diff --git a/Library/Homebrew/compat/requirements/emacs_requirement.rb b/Library/Homebrew/compat/requirements/emacs_requirement.rb
deleted file mode 100644
index c8e2ec274..000000000
--- a/Library/Homebrew/compat/requirements/emacs_requirement.rb
+++ /dev/null
@@ -1,35 +0,0 @@
-class EmacsRequirement < Requirement
-  fatal true
-  default_formula "emacs"
-
-  def initialize(tags)
-    @version = tags.shift if /\d+\.*\d*/ =~ tags.first
-    super
-  end
-
-  satisfy build_env: false do
-    next false unless which "emacs"
-    next true unless @version
-    emacs_version = Utils.popen_read("emacs", "--batch", "--eval", "(princ emacs-version)")
-    Version.create(emacs_version) >= Version.create(@version)
-  end
-
-  env do
-    ENV.prepend_path "PATH", which("emacs").dirname
-    ENV["EMACS"] = "emacs"
-  end
-
-  def message
-    if @version
-      s = "Emacs #{@version} or later is required."
-    else
-      s = "Emacs is required."
-    end
-    s += super
-    s
-  end
-
-  def inspect
-    "#<#{self.class.name}: #{name.inspect} #{tags.inspect} version=#{@version.inspect}>"
-  end
-end
diff --git a/Library/Homebrew/compat/requirements/fortran_requirement.rb b/Library/Homebrew/compat/requirements/fortran_requirement.rb
deleted file mode 100644
index ba3fead6f..000000000
--- a/Library/Homebrew/compat/requirements/fortran_requirement.rb
+++ /dev/null
@@ -1,13 +0,0 @@
-require "requirement"
-
-class FortranRequirement < Requirement
-  fatal true
-
-  default_formula "gcc"
-
-  env { ENV.fortran }
-
-  satisfy build_env: false do
-    which(ENV["FC"] || "gfortran")
-  end
-end
diff --git a/Library/Homebrew/compat/requirements/mpi_requirement.rb b/Library/Homebrew/compat/requirements/mpi_requirement.rb
deleted file mode 100644
index 065b56c8b..000000000
--- a/Library/Homebrew/compat/requirements/mpi_requirement.rb
+++ /dev/null
@@ -1,66 +0,0 @@
-require "requirement"
-
-# There are multiple implementations of MPI-2 available.
-# http://www.mpi-forum.org/
-# This requirement is used to find an appropriate one.
-class MPIRequirement < Requirement
-  attr_reader :lang_list
-
-  fatal true
-
-  default_formula "open-mpi"
-
-  env :userpaths
-
-  # This method must accept varargs rather than an array for
-  # backwards compatibility with formulae that call it directly.
-  def initialize(*tags)
-    @non_functional = []
-    @unknown_langs = []
-    @lang_list = [:cc, :cxx, :f77, :f90] & tags
-    tags -= @lang_list
-    super(tags)
-  end
-
-  def mpi_wrapper_works?(compiler)
-    compiler = which compiler
-    return false if compiler.nil? || !compiler.executable?
-
-    # Some wrappers are non-functional and will return a non-zero exit code
-    # when invoked for version info.
-    #
-    # NOTE: A better test may be to do a small test compilation a la autotools.
-    quiet_system compiler, "--version"
-  end
-
-  def inspect
-    "#<#{self.class.name}: #{name.inspect} #{tags.inspect} lang_list=#{@lang_list.inspect}>"
-  end
-
-  satisfy do
-    @lang_list.each do |lang|
-      case lang
-      when :cc, :cxx, :f90, :f77
-        compiler = "mpi" + lang.to_s
-        @non_functional << compiler unless mpi_wrapper_works? compiler
-      else
-        @unknown_langs << lang.to_s
-      end
-    end
-    @unknown_langs.empty? && @non_functional.empty?
-  end
-
-  env do
-    # Set environment variables to help configure scripts find MPI compilers.
-    # Variable names taken from:
-    # https://www.gnu.org/software/autoconf-archive/ax_mpi.html
-    @lang_list.each do |lang|
-      compiler = "mpi" + lang.to_s
-      mpi_path = which compiler
-
-      # Fortran 90 environment var has a different name
-      compiler = "MPIFC" if lang == :f90
-      ENV[compiler.upcase] = mpi_path
-    end
-  end
-end
diff --git a/Library/Homebrew/compat/requirements/perl_requirement.rb b/Library/Homebrew/compat/requirements/perl_requirement.rb
deleted file mode 100644
index 70eb2a36c..000000000
--- a/Library/Homebrew/compat/requirements/perl_requirement.rb
+++ /dev/null
@@ -1,36 +0,0 @@
-class PerlRequirement < Requirement
-  fatal true
-  default_formula "perl"
-
-  def initialize(tags)
-    @version = tags.shift if /^\d+\.\d+$/ =~ tags.first
-    raise "PerlRequirement requires a version!" unless @version
-    super
-  end
-
-  satisfy(build_env: false) do
-    which_all("perl").detect do |perl|
-      perl_version = Utils.popen_read(perl, "--version")[/v(\d+\.\d+)(?:\.\d+)?/, 1]
-      next unless perl_version
-      Version.create(perl_version.to_s) >= Version.create(@version)
-    end
-  end
-
-  def message
-    s = "Perl #{@version} is required to install this formula."
-    s += super
-    s
-  end
-
-  def inspect
-    "#<#{self.class.name}: #{name.inspect} #{tags.inspect} version=#{@version.inspect}>"
-  end
-
-  def display_s
-    if @version
-      "#{name} >= #{@version}"
-    else
-      name
-    end
-  end
-end
diff --git a/Library/Homebrew/compat/requirements/python_requirement.rb b/Library/Homebrew/compat/requirements/python_requirement.rb
deleted file mode 100644
index 3215d0a6c..000000000
--- a/Library/Homebrew/compat/requirements/python_requirement.rb
+++ /dev/null
@@ -1,68 +0,0 @@
-require "language/python"
-
-class PythonRequirement < Requirement
-  fatal true
-  default_formula "python"
-
-  satisfy build_env: false do
-    python = which_python
-    next unless python
-    next unless short_version
-    # Always use Python 2.7 for consistency on older versions of Mac OS X.
-    short_version == Version.create("2.7")
-  end
-
-  env do
-    if !system_python? && short_version == Version.create("2.7")
-      ENV.prepend_path "PATH", which_python.dirname
-    end
-
-    # Homebrew Python should take precedence over other Pythons in the PATH
-    ENV.prepend_path "PATH", Formula["python"].opt_bin
-    ENV.prepend_path "PATH", Formula["python"].opt_libexec/"bin"
-
-    if system_python?
-      ENV["PYTHONPATH"] = "#{HOMEBREW_PREFIX}/lib/python#{short_version}/site-packages"
-    end
-  end
-
-  private
-
-  def short_version
-    @short_version ||= Language::Python.major_minor_version which_python
-  end
-
-  def which_python
-    python = which python_binary
-    return unless python
-    Pathname.new Utils.popen_read(python, "-c", "import sys; print(sys.executable)").strip
-  end
-
-  def system_python
-    "/usr/bin/#{python_binary}"
-  end
-
-  def system_python?
-    system_python == which_python.to_s
-  end
-
-  def python_binary
-    "python2.7"
-  end
-
-  # Deprecated
-  alias to_s python_binary
-end
-
-class Python3Requirement < PythonRequirement
-  fatal true
-  default_formula "python3"
-
-  satisfy(build_env: false) { which_python }
-
-  private
-
-  def python_binary
-    "python3"
-  end
-end
diff --git a/Library/Homebrew/compat/requirements/ruby_requirement.rb b/Library/Homebrew/compat/requirements/ruby_requirement.rb
deleted file mode 100644
index a9ec8c42d..000000000
--- a/Library/Homebrew/compat/requirements/ruby_requirement.rb
+++ /dev/null
@@ -1,56 +0,0 @@
-class RubyRequirement < Requirement
-  fatal true
-  default_formula "ruby"
-
-  def initialize(tags)
-    @version = tags.shift if /(\d\.)+\d/ =~ tags.first
-    raise "RubyRequirement requires a version!" unless @version
-    super
-  end
-
-  satisfy(build_env: false) { new_enough_ruby }
-
-  env do
-    ENV.prepend_path "PATH", new_enough_ruby.dirname
-  end
-
-  def message
-    s = "Ruby >= #{@version} is required to install this formula."
-    s += super
-    s
-  end
-
-  def inspect
-    "#<#{self.class.name}: #{name.inspect} #{tags.inspect} version=#{@version.inspect}>"
-  end
-
-  def display_s
-    if @version
-      "#{name} >= #{@version}"
-    else
-      name
-    end
-  end
-
-  private
-
-  def new_enough_ruby
-    rubies.detect { |ruby| new_enough?(ruby) }
-  end
-
-  def rubies
-    rubies = which_all("ruby")
-    ruby_formula = Formula["ruby"]
-    rubies.unshift ruby_formula.bin/"ruby" if ruby_formula&.installed?
-    rubies.uniq
-  end
-
-  def new_enough?(ruby)
-    version = Utils.popen_read(ruby, "-e", "print RUBY_VERSION").strip
-    version =~ /^\d+\.\d+/ && Version.create(version) >= min_version
-  end
-
-  def min_version
-    @min_version ||= Version.create(@version)
-  end
-end
diff --git a/Library/Homebrew/compat/requirements/tex_requirement.rb b/Library/Homebrew/compat/requirements/tex_requirement.rb
deleted file mode 100644
index cb26a8477..000000000
--- a/Library/Homebrew/compat/requirements/tex_requirement.rb
+++ /dev/null
@@ -1,20 +0,0 @@
-require "requirement"
-
-class TeXRequirement < Requirement
-  fatal true
-  cask "mactex"
-  download "https://www.tug.org/mactex/"
-
-  satisfy { which("tex") || which("latex") }
-
-  def message
-    s = <<~EOS
-      A LaTeX distribution is required for Homebrew to install this formula.
-
-      Make sure that "/usr/texbin", or the location you installed it to, is in
-      your PATH before proceeding.
-    EOS
-    s += super
-    s
-  end
-end